Functional training is just that. The ability to use the skill sets and techniques being taught.
I haven't trained with swords yet but it's on the list. I'm currently training with my Son to be functional with staff fighting. This doesn't mean that I'm training to be a martial arts staff fighter. It just means I'm learning to be functional with the staff skills that I can use them if I need them. I find enjoyment that my staff skills are not just for show, that I can actually be functional with them.
Things like this appeal to me. If I only train my staff for show then I won't be good in things like this.
You can still be functional with swords. That's what's fencing is. You can take fencing for the enjoyment of it. There's no requirement to compete beyond your club. There's also no push to use a sword in a street fight. You just posses the skill sets to functionally fight with a sword.